Reverse spot facing tool



Oct. 5, 1965 sEllcx-u HlsADA REVERSE SPOT FACING TOOL 2 Sheets-Sheet l Filed sept. le, 1965 awww@ AT TOR N EY@ OC- 5, 1965 sEncHl HlsADA 3,209,653

REVERSE SPOT FACING TOCJL` Filed Sept. 16, 1965 2 Sheets-Sheet 2 ATTORN EVS 7 Claims. (ci. 90-11) This invention relates to a reverse spot facing tool.

The present invention will further be described in detail with respect to an embodiment as illustrated in the accompanying drawings. However, the present invention is not limited by the following descriptions and a modication may be of course possible insofar as it departs from the scope and spirit of the invention as set forth in the appended claims. Similar reference characters are used for similar parts throughout the drawings, in which FIG. 1 is a front elevation of a tool incorporating the present invention with essential parts in section;

FIG. 2 is a sectional view taken along the line 2-2 of FIG. 1;

FIG. 3 is a Vertical sectional side view taken along the line 3-3 of FIG. l;

FIG. 4 is a vertical sectional side view of a part of the tool embodying the invention.

The tool according to the invention comprises a cylinder 1, upper and lower piston cylinders 7, 15 loosely fitted in the upper and lower portions, respectively, of said cylinder 1, and projections 12, 1S provided at the tips of piston cylinders 7, 15 and extending parallel to each other. Clearances 24, 25 are provided between the tips of said projections and the ends of the piston cylinders, and opposed racks 13, 19 are provided on said projections 12 and 18. A toothed wheel 26 is positioned between said racks 13, 19 and has the teeth 27 thereof engaged with the racks. The upper piston 7 is provided with a neck 8 and a shoulder 9, and a cap nut 31 engages with the shoulder 9 and fits loosely around the neck 8 of the upper piston cylinder and is threaded onto the upper end of the cylinder 1. A spring 29 is placed between a spring stop 14 provided on the interior wall surface of the upper piston cylinder 7 and a spring receiving lever 30 provided o n the interior Wall surface of the cylinder 1. Steel ball keys 20, 21 and steel ball keys 22, 23 are tted, respectively, in steel ball holes 3, 4 and steel ball holes 5, 6, provided on the lower ends of vertical grooves 10, 11 for reception of steel balls provided on the exterior wall surfaces of the upper piston cylinder 7 and the lower piston cylinder 15 and also provided on the upper ends of vertical grooves 16, 17 for reception of steel balls and on the interior wall surface of the cylinder 1. A raised portion 2 eX- tends circumferentially on the cylinder 1. Cover rings 32 and 35 are tted together and have necks 33 and 36 on said cover rings loosely engaged on the upper and lower ends of said raised portion 2. A gear shaft 28 has the tooth wheel 26 rotatably mounted thereon and has both ends extending through the cylinder 1. A taper shank 40 is tted on the neck 8 of the upper piston cylinder 7, a connecting rod 43 fitted on the lower piston cylinder 15, and a spot facing cutter 45 removably mounted on a holding rod 42 which is attached to said connecting rod 43. A positioning nut 48 is threaded onto the tip of a positioning rod 46 which is loosely positioned in a vertical bore in a projection 34 provided on the cover ring 32 and is xed to said projection by a screw 47. The numeral 37 indicates a ring groove holding bearing members 38 and 39 for the ends of the gear shaft 28, and 41 indicates a nut for the taper shank 40; 44, a nut for the United States Patent O 3,209,651 Patented Oct. 5, 1965 SCC connecting rod 43; 49, a cap nut; 50, a lock shaft; 51, a handle lever; and 53, 54, 55 and 56 setscrew plugs.

With a structure as above described, the shoulder 9 of the neck 8 of the upper piston cylinder 7 is engaged with the interior wall surface of the cap nut 31, and furthermore, because the steel ball keys 20, 21, the steel ball holes 3, 4 in the cylinder 1 and the lower portions of the vertical grooves 10, 11 for reception of steel balls of the upper piston cylinder 7 are restrictively engaged, the upper piston cylinder 7 cannot be removed from the cylinder 1, and the upper piston cylinder 7 is not moved upward. Moreover, the upper piston cylinder 7 does not fall downward because the spring stop 14 engaged by the spring is restricted by one end of the spring 29 the other end of which is supported by the spring receiving lever 30. As a result, the projection 12 of the upper piston cylinder 7 is not vibrated up and down, and the rack portion 13 thereof restricts the motion of the teeth 27 of the toothed wheel 26, which in turn restricts the motion of the rack portion 19 of the projection 18, thereby controlling the motion of the lower piston cylinder 15. The steel ball keys 22, 23 engage in the steel ball holes 5, 6 of the cylinder 1 and the upper ends of the vertical grooves 16, 17 in the lower piston cylinder 15, and thus vibration and removal of the lower piston cylinder 15 from the cylinder 1 is prevented. Clearances 24, 25 are provided between the tips of the projection 12, 18 of the upper and lower piston cylinders 7, 15 and the ends of the upper and lower piston cylinders 7, 15, respectively, and on the upper and lower ends of the raised portion 2 provided on the circumference of the cylinder 1, the cover rings 32, 35 are threaded together and have engaging portions 33, 36 provided on the cover rings 32, 35 in loose engagement with cylinder 1. The tapered shank 40 is fitted to the neck 8 of the upper piston cylinder 7, and the holding rod 42 is attached to the connecting rod 43 which is tted onto the lower piston cylinder 15. Therefore, the taper shank 40 is held by the upper piston cylinder 7 and is connected securely therewith, the holding rod 42 is held securely by the lower piston cylinder 15 through the connecting rod 43. Thus when the tapered shank 40 is rotated under pressure by means of a drilling spindle 52, the interior surfaces of the vertical grooves 10, 11, 16, 17 for receptionv of steel balls on the upper and lower piston cylinders 7, 15 act on the steel ball keys 20, 21, 22, 23, and the interior wall surfaces of the steel ball holes 3, 4, 5, 6 of the cylinder 1 are acted on by the steel ball keys 20, 21, 22, 23, and the upper and lower ends of the raised portion 2 of the cylinder 1 rotate on the engaging portions 33, 36 of the cover rings 32, 35, together with the upper and lower piston cylinders 7, 15 and the projections 12, 18, and at the same time the toothed Wheel 26 revolves together with the cylinder 1 since both ends of the gear shaft 28 are acted on by the cylinder 1. In the upper piston cylinder 7, the interior wall surfaces of the vertical grooves 10, 11 for reception of steel balls are guided, respectively, by the steel ball keys 20, 21.

Thus the spring 29 is pressed by the spring stop 14 of the upper piston cylinder 7, and is compressed and piston cylinder 7 descends within the cylinder 1, and therefore the projection 12 of the upper piston cylinder 7 is moved downward into the clearance 24, and the toothed p0rtion 27 of the rack portion 13 comes into engagement with the toothed wheel 26 to revolve the latter. The teeth 27 of the toothed wheel 26 engage with the rack portion 19 and move the projection 18 up into the clearance 25, while, in the lower piston cylinder 15, the interior wall surface of the vertical grooves 16, 17 for reception of steel balls are guided, respectively, by the 3 steel ball keys 22, 23, and the lower piston cylinder ascends within the cylinder 1, which in turn raises the holding rod 42 through the connecting rod 43. When revolution of tapered shank 40 by means of the drilling spindle 52 is stopped, the upper piston cylinder stops rotating together with the projection 12, and the steel ball keys 20, 21 are pressed restrictively against the internal wall surfaces of the vertical steel ball-receiving grooves 10, 11, thereby to restrict the internal wall surfaces of the steel ball holes 3, 4. Therefore the cylinder 1 stops rotating, and the steel ball keys 22, 23 are pressed restrictively against the interior wall surfaces of the steel ball holes 5, 6, and thus restrict the interior wall surfaces of the vertical steel ball-receiving grooves 16, 17. Thus the lower piston cylinder 15 stops rotating together with the projection 18, and the holding rod 42 is prevented from rotating further by the lower piston cylinder 15 through the connecting rod 43. Simultaneously the toothed wheel 26 stops rotating together with the cylinder 1 as both ends thereof are restricted by the cylinder 1. Further, the upper piston cylinder 7 rises to the original position within the cylinder 1 together with the projection 12 as the spring stop 14 thereof is pressed by the spring 29, which has been compressed, and the vertical steel ball-receiving grooves 10, 11 are guided, respectively, by the steel ball keys 20, 21, and, at the same time, the rack portion 13 engages with the teeth 27 thereby to revolve the toothed wheel 26, and the teeth 27 engage with the rack portion 19 to press the projection 18, and the vertical steel ball-receiving grooves 16, 17 are guided, respectively, by the steel ball keys 22, 23, and thus the lower piston cylinder 15 descends together with the projection 18 down to the original position. The spot facing cutter 45 is removably mounted on the holding rod 42. As the positioning nut 48 is threaded onto the tip of the positioning rod 46 which is vertically and loosely mounted in the projection 34 provided on the cover ring 32 and fixed thereto by means of a screw 47, the positioning rod 46 can be shifted vertically by loosening the screw 47 thereby to determine beforehand the positions of the cover rings 32, 35 and the work 57. The spot facing cutter 45 is removed from the holding rod 42, the holding rod 42 is put through a hole provided beforehand in the work 57, the screw 47 is tightened to K fix the positioning rod 46 to the projection 34 of the cover ring 32, and the positioning nut 48 is turned either way, whereby the position of the spot facing cutter 45 can be freely adjusted to permit cutting of the work 57 as desired. The holding rod 42 has the spot facing cutter 45 on its tip, and the end of the positioning nut 48 is brought into contact with the work 57, and then the tapered shank 40 is rotated under pressure by means of the drilling spindle 52. When the positioning nut 48 abuts the work 57 and thus stops the movement of the positioning rod 46, this in turn stops the projection 34 and then the cover rings 32, 35. The cover rings 32, hold the upper and lower ends of the raised portion 2 of the cylinder 1 between the engaging portions 33, '36 thereof, thereby to support the cylinder 1. Therefore the cover rings 32, 25 and the cylinder 1 are kept from descending under the pressure of the drilling spindle 52 against the tapered shank 40, and thus permit descent of said upper piston cylinder 7 while revolving within the cylinder 1 and also facilitate ascending of said lower piston cylinder while revolving within the cylinder 1. Thus the spot facing cutter 45 can ascend together with the holding rod 42 while revolving, thereby to cut the work 57 reversely with ease.

What I claim is:

1. A reverse spot facing tool comprising a cylinder, upper and lower piston cylinders loosely fitted in the upper and lower portions of said cylinder and longitudinally guided therein, a toothed wheel means engaging said piston cylinders for moving said upper and lower piston cylinders upwardly and downwardly, a cap nut screwed on the upper end of said cylinder, cover rings fitted loosely around the periphery of said cylinder and secured to each other, a spot facing cutter removably mounted on to said lower piston cylinder, a positioning rod loosely and vertically extending through a projection on one of said cover rings, a screw in said projection to secure said positioning rod to said projection and a tapered shank provided on said upper piston cylinder.

2. A reverse spot facing tool as set forth in claim 1, in which said tooth wheel means comprise projections provided at the tips of said piston cylinders extending parallel to each other, racks provided on said projections, a tooth wheel mounted on a gear shaft on said cylinder engaging with said racks, clearances being provided between said tips of projections and said upper and lower piston cylinders.

3. A reverse spot facing tool as set forth in claim 1, in which said cap nut is engaged with a neck and a shoulder on said upper piston cylinder and loosely fitted on said neck of upper piston cylinder, and a spring provided between a spring stop provided on the interior wall surface of said upper cylinder and a spring receiving lever provided on the interior wall surface of said cylinder for urging said upper piston cylinder upwardly by spring force.

4. A reverse spot facing tool as set forth in claim 1, in which said steel ball keys are fitted in steel ball holes in the interior wall surface of said cylinder and positioned opposite the upper and lower ends of vertical grooves for reception of steel balls provided on the exterior wall surfaces of said upper and lower piston cylinders.

5. A reverse spot facing tool as set forth in claim 1, in which said spot facing cutter is removably mounted on a holding rod which is attached to a connecting rod mounted on said lower piston cylinder.

6. A reverse spot facing tool as set forth in claim 1, in which said positioning rod has a positioning nut adjustably on the tip of said rod.

7. A reverse spot facing tool as set forth in claim 1, in which said cover rings loosely engage the upper and lower ends of a raised portion extending circumferentially on said cylinder.

No references cited.

WILLIAM W. DYER, JR., Primary Examiner. 

1. A REVERSE SPOT FACING TOOL COMPRISING A CYLINDER, UPPER AND LOWER PISTON CYLINDERS LOOSELY FITTED IN THE UPPER AND LOWER PORTIONS OF SAID CYLINDER AND LONGITUDINALLY GUIDED THEREIN, A TOOTHED WHEEL MEANS ENGAGING SAID PISTON CYLINDERS FOR MOVING SAID UPPER AND LOWER PISTON CYLINDERS UPWARDLY AND DOWNWARDLY, A CAP NUT SCREWED ON THE UPPER END OF SAID CYLINDER, COVER RINGS FITTED LOOSELY AROUND THE PERIPHERY OF SAID CYLINDER AND SECURED TO EACH OTHER, A SPOT FACING CUTTER REMOVABLY MOUNTED ON TO SAID LOWER PISTON CYLINDER, A POSITIONING ROD LOOSELY AND VERTICALLY EXTENDING THROUGH A PROJECTION ON ONE OF SAID COVER RINGS, A SCREW IN SAID PROJECTION TO SECURE SAID POSITIONING ROD TO SAID PROJECTION AND A TAPERED SHANK PROVIDED ON SAID UPPER PISTON CYLINDER. 